Insulator with caps



Jan 19, 1932.

K. A. HAWLEY INSULA'I'OR' WITH CAPS Filed March 1, 1930 IIHHI L Vii 44,

Patented Jan. 19, 1932 UNITED srArasYrA rENT OFFICE KENT a. HAW'LEY, o .mn'rmonn :HARY'LAND, ASSIGNOR ,TO LOCKE msum'ron coaroaarron, or summons, MARYLAND, A coaroaarron or MARYLAND msumrroa one Application filed llaroli'l,

caps having holes therein for the attachment of clamps, switch elements, bus bars and the like thereto. It is usually customary to form these caps of malleablecastings and as ta ped holes are provided for the reception the screws used for attaching accessories to the insulator, fairly heavy'bosses are provided at the holes. These large and heavy bolt bosses always contain soft spots in the middle and generally shrink'cracks aroundthe edges. Furthermore it is customary to drill the holes part way through the cap as otherwise if a bolt or. screw of excessive length were used it would contact the porcelain and probably force the cap ofi. As a consequence the heavy bosses are of considerably greater depth'than the holes therein, often actually one-fourth inch to three-eighths inches thicker than the effective length of thethreaded hole. Another disadvantage is that considerable care mustbe exercised in tapping the holes especially as different tools are necessary to make the thread proper throughout the length of the hole.

It is with all of the'above facts in view that I have devised the present invention which has for its principal object the provision of an insulator cap wherein the thickness of the bosses may be greatly reduced so that the overall height of the insulator will be decreased, without sacrificing any of its insuwill be diminished.

An important object of the invention is to provide an insulator cap which may bemade of forged steel and in which the tapped holes for the reception of screws or bolts may be formed clear through the cap and subsequent ly closed or covered by special means.

An additional object of the invention is to provide a cap construction possessing these advantageous characteristics and which will at the same time be simple and inexpensive of the icorrect length when attachin 1930. Serial No. 432,490.

to make, and a general improvement in the art;

To the attainment of the foregoing and other objects andadvantages, the invention panying drawings in which:

Figure 1 is a fragmentary view of a pedestal insulator equipped with my improved cap, thecap being partly broken away and in section, and v i Figure2 is a plan view of the cap with a portion thereof broken away and in section.

Referring more particularly to the drawings, it will be observed that I have disclosed a portion of an insulator of the pedestal type in which the porcelain body is usually provided throughout at least the major portion of its length with ribs or corrugations 11 1 and provided at its upper end with a reduced taperedextension'12 upon whichis mounted the.cap 13. Inthe carrying out of my invention this capis preferably formed as a steel "forgin'g'and is of the usual general design in so far as shape is concerned, the size necessarily 'depen'dingflupon the particular insulator.- At spaced points the top wall 14 of the cap is thickened at its'juncture with the side wall 15, as shown at 16, andthrough these thickened portions holes 17 are drilled, these holes extending clear through and being tapped. Unless care be taken to use bolts 18 accessories to the insulator, it is conceiva le that the-bolts might engage upon the top ofthe lating value and so that cantilever strains insulator body and force the cap AS was employment of an obstructing element cover- "ing the lower end of the hole and secured to" .7 the undersideof thethickened portion at the hole. This might conceivably be a small disk or plate. for each hole but I prefer to make use of a simple metal ring -19, which may be of comparatively thin steel, located within the" cap, lying against the underside of all of the thickened portions and positively secured thereto, for instance by welding. Such a ring requires only one operation for its securing whereas individual hole closure means would require four operations and consequently additional labor in assembling the parts. This ring constitutes adequate means for preventing the screws 18 from being inserted too far and also serves as means to prevent access of water or moisture to the interior of the cap.

The cap having been formed in this manner is placed upon the reduced end 12 of the insulator body and secured thereon by the usual cement mass 20.

The insulator equipped with the improved cap is of course used in the same manner as any other of the same type but possesses the advantage that the actual height of the thickened portions 16 is reduced as compared with the height of such in cap constructions where there are bottomed holes for the screws. The overall height of the insulator is consequently reduced, the thickness of the central portion of the mass of cement 20 is decreased, and

the cantilever strains on the porcelain diminished. The appearance of the insulator is of course improved but the principal advantage is the added durability and efficiency as the shortening of the overall height does not in any way detract from the electrical efficiency, the leakage path being of the same length as if the insulator had not been shortened. It is believed that the construction, operation and advantages will be apparent to one skilled in the art without further explanation.

lVhile I have shown and described the preferred embodiment of the invention, it should be understood that the disclosure is merely an exemplilication of the principles involved as the right is reserved to make all such changes in the details of construction as will widen the field of utility and increase the adaptability of the device provided such changes constitute no departure from the spirit of the invention or the scope of the claims hereunto appended.

Having thus described the invention, I claim:

1. In an insulator, a dielectric body, a met :11 cap secured upon the end of the body, said cap having its top wall provided with holes extending clear through, and imperforate metallic closure means united to the underside of the top wall of the cap for covering said holes.

2. In an insulator, a dielectric body and a cap secured up one end thereof, the cap being provided on the inner side of its end wall with thickened portions merging into the side, said thickened portions being formed with tapped holes extending entirely therethrough, and metallic plate means secured to the underside of said thickened portions for covering said holes.

3. In an insulator, a dielectric body and a metallic cap secured upon the upper end thereof, said cap being provided with a plurality of threaded holes extending clear through its top, and an annular imperforate metallic plate means lying against the underside of the top wall for closing all of said holes.

4. In an insulator, a dielectric body and a metallic cap secured upon the upper end thereof, said cap being provided with a plurality of: threaded holes extending clear through its top, and metallic plate means secured on the underside of the top wall for closing said holes, said means being formed as a ring.

5. In an insulator, a dielectric body and a metallic cap secured upon the upper end thereof, said cap being provided with a plurality of threaded holes extending clear through its top, and metallic plate means secured on the underside of the top wall for closing said holes, said means being formed as a ring welded in place.

6. In an insulator, a dielectric body, a metallic cap secured upon the upper end thereof, said cap being provided with a plurality of holes extending clear tlu'ough its top, and a metallic ring united to the underside of the top wall of the cap for closing said holes.

In testimony whereof I afiix my signature.

KENT A. HAWVLEY. 

